Income Taxes (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Income Tax Contingency [Line Items] | ||||
| Effective income tax rate (as a percent) | 22.00% | 13.00% | 22.00% | 16.00% |
| Deferred income taxes | $ 74 | $ 200 | ||
| Interest and penalties on uncertain tax liability | $ 30 | 30 | ||
| Increase in unrecognized tax benefits is reasonably possible as a result of a lapse in statutes | $ 11 | $ 11 | ||
| Houston Electric | ||||
| Income Tax Contingency [Line Items] | ||||
| Effective income tax rate (as a percent) | 20.00% | 20.00% | 20.00% | 20.00% |
| Deferred income taxes | $ 20 | $ 18 | ||
| CERC | ||||
| Income Tax Contingency [Line Items] | ||||
| Effective income tax rate (as a percent) | 11.00% | 24.00% | 22.00% | 19.00% |
| Deferred income taxes | $ 12 | $ 12 | $ 38 | $ 92 |